Mechanical elements with nonlinear mechanical impedance have a variety of applications. Crushable materials, for example, or crush zones in vehicles, provide protection from shock or impact, i.e., large loads of short duration. Such materials or structures absorb mechanical energy and are permanently deformed, i.e., damaged. As a result, such a material or structure may not provide protection from repeated impacts.
In some applications, large loads may occur repeatedly, as, for example, if the hull of a boat on rough seas repeatedly impacts the faces of large waves. In such circumstances it may be desirable, for example, to protect cargo on the boat from the shock of these impacts. Thus, there is a need for a nonlinear mechanical element which deforms without damage when subjected to a threshold load, and returns to an un-deformed state after the load is removed.